Mozambican police fired tear gas at thousands of opposition protesters in the capital Maputo on Thursday amid disputed election last month.
The ruling Frelimo party was declared winner of the disputed election by the electoral commission.
Anger has mounted since election authorities said Frelimo had won the Oct. 9 vote, extending its 49-year rule.
Human rights groups say at least 18 people have been killed in the police crackdown on protests since then.
The election was hotly contested, with many young people supporting independent candidate Venancio Mondlane, who says the vote was rigged and encouraged demonstrations.
Protesters chanted “Power to the people” and “Frelimo must fall” and some blockaded streets with burning tyres and held homemade signs supporting Mondlane.
“This is it. If we don’t stand up now, nothing will change,” said Julia Macamo, 55, a street vendor and mother of six who was still shaken by the tear gas she inhaled while protesting in the Maxaquene neighbourhood. “It’s time to see the back of Frelimo.”
Adriano Nuvunga, director of Mozambique’s Centre for Democracy and Human Rights, said the country had never seen such large demonstrations.
Civil society groups and Western observers also said the election was unfair and that results were altered. A Frelimo spokesperson did not respond to requests for comment.
The party has been accused of vote-rigging in previous polls and has denied it. This sparked smaller protests last year.
President Filipe Nyusi has not spoken since the protests escalated. His defence minister has threatened to deploy the army and warned against attempts to grab power.
Mozambique’s Constitutional Council has not yet certified the election results, a process that usually takes around two months.
On Tuesday it ordered the electoral commission to clarify within 72 hours why there had been discrepancies in the number of votes counted in the presidential, legislative and provincial elections, according to a letter seen by Reuters.
An electoral commission spokesperson did not immediately respond to a request for comment.
Many Mozambicans have expressed frustration at lack of economic opportunities while the country is rich in natural resources.